LONDON (Reuters) – Britain’s Prime Minister Theresa May will push ahead with plans to fix into law the time and date of the country’s European Union exit for March 2019, her spokesman said on Friday, despite opposition from some members of her party.

FILE PHOTO: Union Flags and European Union flags fly near the Elizabeth Tower, housing the Big Ben bell, during the anti-Brexit ‘People’s March for Europe’, in Parliament Square in central London, Britain September 9, 2017. REUTERS/Tolga Akmen/File Photo

“We think it provides important certainty,” the spokesman said. “We would encourage all MPs to support it,” he added, referring to members of parliament.

Reporting By David Milliken, Writing by Andrew MacAskill, editing by Kate Holton